Method and apparatus for the manufacture of hollow articles



Jan. 19, 193 2. v w. DARWIN I R'e. 18,334

METHOD AND APPARATUS FOR THE MANUFACTURE OF HOLLOW ARTICLES Uriginal 5 93 sh ts sheet 1 7 Re. 18,334 owmrxcnm Ja 19, 1932, I w. P. DARWIN METHODAND APPARATUS FOR JHE MANUEACTUBR OF 501,1,

Oiigihal Filed July 6, 1926 3 Sheets-Sheet 2 W. P. DARWIN R METHOD ANDAPPARATUS FOR THE MANUFACTURE OFHOLLQW ARTICLES 3 Sheets$heat Jan. 19,1932.

.n Ma H m a a w Original Filed July 6, 1926 Reissued Jan. 19, 1932UNITED STATES PATENT oF rcE WALTON P. DARWIN, OF WASHINGTON,

DTSTRICT OF COLUMBIA, ASSIGNOB, Bi MESNE ASSIGNMENTS, TO THE BARRETTCOMPANY, OF NEW YORK, N. Y., A'CORIEOIRIA- TION or NEW JERSEY METHOD ANDAPPARATUS FOR Original 30. 1,648,475,:1ated November 8,

THE MANUFACTO'RE OF HOLLOW ARTICLES I 1927. Serial No. 120,834, filedJuly 6, 1926. Application for reissue filed June 20, 1930. Serial No.462,645.

plastic material upon a collapsible core and thereafter compressingthese layers and smoothing the outer surface during the rota: tion ofthe core in such manner as to provide for a plurality of such layers.The successive layers according to my improved method may be of similarmaterial or may be of different plastic materials reinforced or not asmay be demanded by the ultimate use to which the articles. are to beapplied.

In carrying outthe above methods my invention includes the provision ofan improved collapsible core alone or in combination with retainingmeans which serve temporarily to hold the core in adjusted position andat the same time limit the extent to which the plastic material may beapplied to the core.

It is a further object of my invention to provide a feeding device foruse in applying successive layers'of plastic material to a core whichmay be brought into receiving position with respect to the hoppers.

Another object of my invention is to provide means for carrying out theoperation of or otherwise treating the plastic material immediatelyafter the same is delivered from the hoppers. This means is arranged tosupply a. varying pressure upon the plastic material.

It is a further object of my invention to rolling, compressing providemeans for carrying out the subsematerial such as con- As illustrative ofone preferred form of device in which my invention may be embodied, Ihave shown on the accompanying draw-' ings, mechanism according to theabove description and in which 1 Fig. 1 is a side elevation of a moldingdevice;-

B Fig. 2 is a vertical section on line22 of Fig. 3 is-a diagrammaticview showing the method of applying a reinforcing wire betweensuccessive layers of the material;

.- r Fig. 4 is a transverse section of one form of core and thecorresponding hollow article;

Fig; 5 is a transverse section of a core showing a modified form ofarticle, and

Fig. 6 is a transverse section showing the core adapted for moldingpartly circular articles.

- The mechanism for carrying .out this invention is shown to be mountedupon two parallel rails 7, 7 to which vertical standards 8, 8 arebolted.

connected by meansof cross bars 9. The cross bars 9 support a pair oflongitudinal carrier tracks 10, 10.

While the tracks 10, 10 are shown to be supported only from standards 8,8, it will be evident that they may form part of any appropriatesuppOrtlng structure, it being only necessary that the tracks lO bemaintained substantially horizontal and parallel to the Tails 7, 7.

Depending supports 11,11, having rollers 12, 12 are supported and inturn support a hopper device 13.

The hopper device 13 consists of a luralit of compartments such as. 14,15 an 16 eac adapted to carry material of different character. Thehopper compartment 14 has abettom valve 17 while hopper compartment 15is closed by the valve 18. The valve 19 closes the bottom ofcompartment- 16. The valves 17, 18 and 19 may be manually andindependently controlled to permit the flow of a predetermined quantity'of plastic material onto the core or partially to discharge materialonto the core at one side of the vertical diameter of the core. As theThe upper ends of the ver- 'tical standards are from the tracks 10, 10

formed pipe. The 1 hopper 13, it will be noted, is positioned core isrotated in the direction indicated by the arrow in Fig. 2, the materialdeposited thereon is moved upwardly from the point of application andthen downwardly to a point where it is contacted with the screed orspreader member 31 hereinafter described. The material applied to thecore, it will be noted, is supported by the core during/the rotationthereof until the core leaves the spreader member 31, at which point thematerial has set and hardened so that it adheres to the core.

Brackets 20, 20 are mounted upon the forward side of the hopper device13 in the manner indicated in Fi 1.. Beneath each bracket 20, 20 ismounted-a link 21, pivoted to the wall of the member 13. The ends of thelinks.

21 serve as journals for a roller 22. Vertical adjusting rods 23 connectthe links 21, 21 with brackets 20, 20 and by means of screw threads onthe rods 23 and hand wheels 24 the position of the roller 22 may bevaried.

Slidably journaled by means'of collars 25, 25 there is carried abar 26extendin horizontally between the standards 8, 8. 26 carries verticalsupporting rods 27, 27, hich terminate at their lower ends in bifurcatedportions 28, 28. These portions serve as journals for rollers 29, 29. Bymeans of screw threaded adjustments of-the rods 27, 27 the position ofthe bar 26 ma be varied with respect to the core upon whi lithe rollers29, 29 are adapted to rest.

A web 30 is bolted or otherwise attached to bar 26 and extendsdownwardly and to the rearthereof. The web 30 terminates in asubstantially flat flexible plate or screed 31 which extends equaldistances on opposite sides of the web 30.

Bars 32, 32 are held rigidly by the'web 30 in a position spaced abovethe member 31.

Adjusting bolts 33, 33, screw-threaded transversely through the rigidmembers 32, 32 serve to apply pressure upon one or both sides of thesmoothing plate 31, and thus to vary its inclination with respect to theweb 30 and the bar 26.

Standards 8, 8 each carry a sliding collar 34, 34. The standards arealso slotted vertically as at 35 inFig. 2 to receive a transverse shaft36. The position of the shaft 36 is determined by vertical adjustment ofthe sliding collars 34, 34. Suitably arranged between standards 8, 8,and journaled fixedly on the shaft .36 are two supporting rollers 37,37.

One end of the shaft 36 is extended beyond standard 8 to receive apulley or other dri'ving means 38. The rails 7, 7 form a track forindividual carriages 39 also having vertical standards 40 slotted toreceive a horizontal shaft 41 carrying similar supporting rollers 42.Adjustable collars 43 are mov-' able vertically on standards 40. Anysuitable means may be employed for maintaining the adjustment screws 4 1alreadystdescribed and carriages 39 in the desired position on the rails7, 7

A substantially cylindrical core 44 is shown to be split longitudinally.

U-shaped brackets 46 are attached across the slotted portion of the core44 and carry A wedge 48 is supported by the adjustment screws 47 andfits within the slotted portion of the core 44, with ears 45, 45 incontact with the core.

Mounted upon the opposite ends of the outer surface of core 44 are rings49, 49'each having an upstanding flange 50, 50. The rings are split asshown in Figs. 1. and 2 and have upstanding'lugs 51 which are adapted tobe. bolted together by means of bolts 52,.52.

In Fig. 3 there has been shown diagrammatically a means for wrappin areinforcing wire' 53 from a spool 54 an around the core and itssuperposed material. -This means is indicated as a traveler 55 caused toreciprocate on track 56 by means of an endless chain 57 driven over apair. of sprocket wheels 58 from. a shaft 59 which may be geared to thedrive pulley 38 in the usual manner.

In this manner reinforcing wire may be wrapped spirally around the al'and embodied in its upper surface from end to end. vThe ratio betweenthe rotation of shafts 36 and 59 may be'adjusted to con trol the numberof turns of wire applied evenlyover the material.

TlllS invention lends itself to the manufacture of diverse forms ofarticles of which several are illustrated in Figs. 4, 5 and 6.

Where concrete pipes are subjected to vertical loads as for example inculverts and the like, it is found that toward fracture on the inside ofthe pipes along their vertical diameters and on the outside of the pi esalon their horizontal diameters. In ig. 4 t ere is shown a pipe moldedof concrete or the like in the manner particularly adapted to wit andthis tendency. The core 60 is of special oval cross section andsplit forthe purpose already described in connection with the circular core 44.When this core is used in the machine illustrated in Fig. 1, the screedand its mounting are fixed upon the standards 8, 8 and the core 60supported directly upon the vertically adjusted rollers 37 and 42. Thefirst layer of material 61 will be circular in outer configuration afterwhich wire or analogous material 53 will be applied as alreadyindicated. The screed 31 will then be released from standards 8, 8 andsupported upon rollers 29, 29 in contact with the core 60. On pouringthe second layer of concrete 62 the latter will take the same outerconfiguration as the core 60 and consequently will provide a pipe ofuniform thickness. In this way the reinforcing elements 53 will there isa tendency molded materibe brought toward the outer surface along thehorizontal axis H, H, while they will be nearer the vertical axis VV. Inthis way the reinforcing is placed in the material at the point where itis most effective in overcoming stresses.

In Fig. 5 a circular core 44 has been shown to be covered first with onelayer 63 of material and the outer surface thereof formed with keydepressions 64 at frequent intervals. These depressions may be producedby the use of special forms of rollers 22. After the first layer iswrapped with spiral reinforcing rods 53 a second layer 65 is moldedhaving an inner surface occupying the keyrecesses 64 and an outercylindrical surface. In this wa the reinforcing element 53 may be moreeasi y buried within the semi-plastic outer surface of the layer 63 anda closer bond may be established between the layers 63 and 65.

In Fig. 6 there has been shown the use of the circular core 44 for thepurpose of molding partly circular articles such as roofing tile and thelike. This is accomplished by attaching to the outer surface of the core44 a series of longitudinal strips 66 extending a substantial distanceabove the surface'of the core. The material molded upon such a devicewill take the form'of concavo-convex slabs 67. I I

In 0 eration of the mechanisms above describe it is to be understoodthat core 44 lsspread by means of wedge 48 into close binding contactwith the end rings 50. The

core is then supported upon the rollers 37 and 42 and the latteradjusted vertically to bring the surface of the core to a positionspaced beneath the hopper device 13 by a desired distance. The carriage39 for rollers 42 is locked into position on rails 7, 7 and the hopperdevice brought forward and locked into position over the core. Thescreed, or

spreader member 31 will control the ultimate thickness 8, 8 at anadjusted height above core 44 by means of the adjustment I 27 so thatthe screed 31 will control the ultimate thickness of the layer 61. It isevident that the rollers 29 rest upon the ends of the core 44. Roller 22is support'ed'in like manner in adjusted relation from the hopper device13'. Plastic material is then allowed to flow from one of thecompartments in the hopper structure 13. As shown in Fig. 2 compartment16 is adapted for holding asphalt or other bituminous material; hopper14 carries gravel or other loose material, while the other intermediatecompartment 15 is delivering a mixture of fluent plastic bindingmaterial; As the'mixture flows on to the core 44 it is compressed androlled by means of. roller 22 which may by its adjust-- ment transmitagainst the plastic material a greater part of the weight of the hopperstructure 13 and its contents thus effectually compacting the layer ofmaterial. As the core is slowly rotated this material is broughtunderthe screed 31 which is adjustable in its tilting to give the appropriatesmoothness of finish to the material. The continued slow rotation ofcore 44 will in this manner cause a complete layer 61 to be deposited.If desired the core and its molded pipe layer may belowered from rollers37 and 42 and set aside to harden.

However in Fig. 3 the completed layer is shown in the process of beingwrapped by means of spiral turns of the reinforcing wire 53. Layer 61may also be covered with a similar layer of material such as asphaltfrom compartment 16 or gravel from compartment 14 either of which maybeincorporated in layer 61 by roller 22 and screed 21. In like manner asecond layer 68 may be applied in the above manner and these stepsrepeated until the desired thickness of the pipe is attained.

As shown in Fig. 1 the screed 31 is extended at one end to provide araised portion which causes the pipe or other cylindrical casting totake a corresponding enlargement at the end.

It will be evident that the same rocedure will be carried out .inthemanu acture of the devices shown in Figs. 4, 5 and 6'.

After the casting is completed the core and casting are removed forhardening and the core ultimately contracted for separation. Wherecircumstances make it desirable, the core may be a complete cylindricalpipe or the like to which the casting is permanently applied. In themanufacture of curved tile and the like as shown in Fig. 6

.the hardened articles may be removed from the core without contractingthe latter.

This procedure and the mechanism above described is applicable to themanufacture ofpipes, columns, tile and other like articles as will beevident from the above description. While one preferred form of myinvention has been described numerous changes in minor details may becarried 0 it without departing from the scope of the invention ascomprised in the appended claims.

I claim: 1. The method of forming tubular articles which consists offeeding a layer of plastic material simultaneously over the desiredlength of a slowly rotated core and successively rolling and smoothingthe material to the thickness desired.

2. The method of forming tubular articles which consists of, feeding alayer-of plastic material simultaneously over the' desired length of aslowly rotated core, successively compacting and gauging the material tothe thickness desired, incorporating relnforcing elements in the outersurface of the layer of material, feeding a second layer of material inlike ma nner, compacting the layers through the reinforcing elements andhardening the material. v

5. The method of forming tubular articles from slowly hardening fluentmaterial which consists in feeding a layer of fluent material on theupper surface of a slowly rotated core, then immediately compactingandsmoothing the material by successive steps while the material is heldto the core by gravity.

6. In a machine for molding hollow articles, a tubular core, end ringscarried thereby, means for rotating the core, plastic material feedingmeans and means for elevating the core into adjusted spaced positionrelative to the feeding means. 7

7. In a machine for molding hollow articles, a tubular core, and ringscarried thereby me ans for rotating the core, a feed hopper, a presserroll pivotally journalled on the hopper and means for adjusting the rolli'ela tive to the hopper outlet.

5 tating the core and 8. In a machine for molding hollow arti-- cles, atubular core, end rings carried thereby, means for rotating the core, afeed hopper having a plurality'of separate compartments with paralleladjacent outlets extend-' ing axially of the core.

9. In a machine for molding hollow articles, a tubular core splitaxially, a wedge member, means for, radially through the split portionof the core, end rings carried by the core, means for roplastic materialfeeding means spaced from the outer surface of the core.

10. In a machine for molding hollow articles, a tubular core splitaxially, a wedge member, means for moving said member radially throughthe split portion of the core,

contractible end rings carried by the core, means for rotating the coreand plastic material feeding meansfspaced from the outer surface of thecore.

v 11. In a machine for molding hollow articles, a tubular core,"endrings carried by the core, means for rotating the'core and plasticmaterial feeding means movable transversely into and out of deliveringposition opposite the core. I V

moving said member 12. In a machine for molding hollow articles, atubular core, end rings carried by the core, means for rotating thecore, plastic ma-- terial feeding means extending axially of the core,an independent support means for varying the )osition of said materialfeeding means adjustably in its distance from the independent supportand under operatingv conditions, and a screed on the support parallel tothe feeding means.

13. In a machine for molding hollow articles, a tubular core, end ringscarried by the core, means for rotating the core, plastic materialfeeding means extending axially of the core an independent support, acarriage vertically slidable on the support, and a screed carried by thecarriage. Y

14. In a machine for molding hollow articles, a tubular core, end ringscarried by the .core, means for'rotating the core, plastic materialfeeding means extending axially of the core, an independent support, acarriage vertically slidable on the support, a creed carried by saidcarriage and means for tilting the screed.

15. In a machine for molding hollow articles, a substantiallycylindrical core, a wedge for expanding the same, adjustable flangedsplit-rings for limiting the expansion of the core and for confining theends of the article molded, means for revolving the core, means forelevating the same, a plurality of hopper compartments extending thefull distance be-' tween the split-rings, and movable transversely ofthe core and into feeding position with relation thereto, a presserroller pivotally carried by the hopper compartments, means for adjustingthe presser roller with respect to the core, a screed parallel to andco-extensive with the hoppers, means for slidably and adjustablysupporting the screed above the core, and means for tilting the screed.

16. The steps in the method offorming a coated pipe which compriserotating a pipe whilev in substantially horizontal position, applyingfluid plastic material to the top of said pipe, smoothing the plasticmaterial simultaneously with the rotation of the pipe by a spreadermember positioned adjacent the side. of said pipe in flat contact withthe coating material on said pipe and,contacting with the-coatingmaterial on said pipe at a pointremoved from the region of applicationof the fluid plastic material to the top of the pipe, said memberfunctioning to form a smooth layer 'of' said coating material about thepipe, said pipe in its rotation-carrying the plastic material intocontact with the member which uniformly spreads the coating materialthereabout.

17. The method of applying coating ma-- terial to a tubular articlewhich comprises supportingthe article so that the upper r tiont-heIEOflS exposed, rotating the article,

applying plasuc bituminous material to the top of said article while itis being rotated, the plastic 'material being at such tem erature thatit is fluid, smoothing the p astic material and forming a layer of 'suchmate rial of desired thickness on the'article by contacting the plasticmaterial thereon during the rotatio'nthereof with a spreader-positionedadjacent the side of the tubular arti- (lo in flat contact with thecoating material on said article and at a-point removed from the regionof ap lication of the fluid plastic materialto the top of said article.

' 18. The herein described method of applying coating material to apipe, including first revolving the "pipe, applying the coating materialwhile hot and in fluid condition onto' the top of the pipe and applyinga spreader at a point removed from the region of application of the hotfluid coating material onto the top of the pipe and inflat contact withthe coating material to uniformly spread the coating and to preventoverflow of excess coating.

19. The method of forming tubular articles which comprises rotating :1core while in substantially horizontal position, pouring fluid plasticmaterial onto the top of said core at a point on said core somewhat toone side of the vertical diameter thereof, said core being rotated in adirection to cause said plastic material as applied to be supportedbysaid core and thus prevent flow of the plastic material off of saidcore, and forming a. layer on said core by contacting plastic;

material thereon during the rotation thereof with a spreader positionedadjacent the side of said core flat contact with the coating material onsaid core at a point removed 40 from the region of application of thefluid plastic material'to said core, the spreader functioning to providea smooth, even coating of said material on said core.

20. The method of applying coating material to tubular, articles whichcomprises supporting the article in a horizontal position so that theupper portion thereof is exposed, rotating the article, applying plasticbituminous material in a fluid condition to the top of said article,while it is being rotated, to one side of the vertical diameter of saidtubular article, smoothing the plastic material and forming a layer ofsuch materi al of desired thickness on the article by cont'aeting' theplastic material thereon during the rotation thereof with aspreader'posi tioned on the other sideof the vertical diameter ofthetubular article adjacent the side of,the tubular article in flatcontact withthe 00 coating material on said articlel In testimonywhereof, I have hereunto affixed my signature. I I WALTON P. DARWIN.

